The Twisted One
Well-Known Member
When I went commercial hydroponics, we were introduced to a lot of things personal growers don’t run into. One biggy was heat build up in the four reservoirs of the flower room. I figured a one hp chiller would do, but quickly learned it simply couldn’t keep up, and reservoir temps were out of control.
So I began pricing large chillers and what I learned was they aren’t cheap. Bad news for me, ESPECIALLY at that time. So I began doing what I like to do-research.
Mind you, I’m an HVAC tech and know air conditioning, so how hard could it be? Considering how unconventional I am, and I didn’t have 8-10 grand, I improvised. Here’s how, but first, let’s keep it simple. A chiller is just like your AC at home, except it cools water instead of your evaporator coil that cools air moving across it. What this means is we need an evaporator coil designed to chill water and pump to move the water through it.
First up is to build a frame large enough to contain the chiller evap, a dependable pump (used a shallow well pump I bought used from marketplace) , and the control electronics. I had to order the chiller coil, but the rest of the project was sourced from used parts except for the gauges I chose to install so both high and low side pressure can be monitored with a simple visual glance.
So first up is to build a frame to hold it all. I dig 1x1 and 1x2 square tubing, and always have scraps laying around. Cheap and easy.
Grabbed some leftover’s and built a frame to house everything. I decided on using an INKBIRD temperature controller, mainly because they work and face it. 20 bucks for a temperature controlled solution with time delay capabilities? I did purchase a quality stainless steel temp probe for another 20 bucks. Heck yea. A 40 dollar solution when there isn’t a pre built one anyway.
I then grabbed some aluminum and made a faceplate for the controls and gauges.
I took the power supply inlet from an old computer for another cheap plug in solution
Next up was mounting the pump. Under this controller sits a 275 gallon reservoir that is maintained at 64 deg f. The shallow well pump draws water from the reservoir into the chiller coil and back into the reservoir.
It may look complicated, but it’s really pretty straightforward. The Inkbird is used to power a relay responsible for bringing the outdoor condensing unit on. It also provides a 5 minute time delay, another required safety. More on that later.
I installed a keyed lockout and an emergency shut off, well, just because, and if it goes south when I’m not there, a simple push of the red button shuts her down.
7/8” and 3/8” copper lines connect to the chiller evaporator and lead outside to a simple, used residential condensing unit found at any home today. This one is rated at 5 tons, and a 5 ton chiller evap was purchased for the project. This was over 300 bucks alone. Pricey, but look what we are getting.
We just need to add a little device missing on all condensers that allows this one to safely and efficiently run in both summer and winter. What it does is intelligently control the condenser fan motor, and do so based upon coil temperatures. It the temperature probe senses freezing, it disables the fan to allow the compressor pressures to stay high and prevents liquid refrigerant from migrating back to the compressor, a big no-no.
What this does (and has faithfully done for several years now) is to very easily allow me to maintain all my reservoirs to a balmy 68 deg, plus or minus 1 deg. I simply pump chilled water into loops located in each reservoir, basically into home made Wort chiller coils. This allows me to maintain over 80 degree room temps under sealed room Co2 supplement while maintaining those perfect root zone temps. Perfect conditions for explosive growth!
Hope you enjoyed!
So I began pricing large chillers and what I learned was they aren’t cheap. Bad news for me, ESPECIALLY at that time. So I began doing what I like to do-research.
Mind you, I’m an HVAC tech and know air conditioning, so how hard could it be? Considering how unconventional I am, and I didn’t have 8-10 grand, I improvised. Here’s how, but first, let’s keep it simple. A chiller is just like your AC at home, except it cools water instead of your evaporator coil that cools air moving across it. What this means is we need an evaporator coil designed to chill water and pump to move the water through it.
First up is to build a frame large enough to contain the chiller evap, a dependable pump (used a shallow well pump I bought used from marketplace) , and the control electronics. I had to order the chiller coil, but the rest of the project was sourced from used parts except for the gauges I chose to install so both high and low side pressure can be monitored with a simple visual glance.
So first up is to build a frame to hold it all. I dig 1x1 and 1x2 square tubing, and always have scraps laying around. Cheap and easy.
Grabbed some leftover’s and built a frame to house everything. I decided on using an INKBIRD temperature controller, mainly because they work and face it. 20 bucks for a temperature controlled solution with time delay capabilities? I did purchase a quality stainless steel temp probe for another 20 bucks. Heck yea. A 40 dollar solution when there isn’t a pre built one anyway.
I then grabbed some aluminum and made a faceplate for the controls and gauges.
I took the power supply inlet from an old computer for another cheap plug in solution
Next up was mounting the pump. Under this controller sits a 275 gallon reservoir that is maintained at 64 deg f. The shallow well pump draws water from the reservoir into the chiller coil and back into the reservoir.
It may look complicated, but it’s really pretty straightforward. The Inkbird is used to power a relay responsible for bringing the outdoor condensing unit on. It also provides a 5 minute time delay, another required safety. More on that later.
I installed a keyed lockout and an emergency shut off, well, just because, and if it goes south when I’m not there, a simple push of the red button shuts her down.
7/8” and 3/8” copper lines connect to the chiller evaporator and lead outside to a simple, used residential condensing unit found at any home today. This one is rated at 5 tons, and a 5 ton chiller evap was purchased for the project. This was over 300 bucks alone. Pricey, but look what we are getting.
We just need to add a little device missing on all condensers that allows this one to safely and efficiently run in both summer and winter. What it does is intelligently control the condenser fan motor, and do so based upon coil temperatures. It the temperature probe senses freezing, it disables the fan to allow the compressor pressures to stay high and prevents liquid refrigerant from migrating back to the compressor, a big no-no.
What this does (and has faithfully done for several years now) is to very easily allow me to maintain all my reservoirs to a balmy 68 deg, plus or minus 1 deg. I simply pump chilled water into loops located in each reservoir, basically into home made Wort chiller coils. This allows me to maintain over 80 degree room temps under sealed room Co2 supplement while maintaining those perfect root zone temps. Perfect conditions for explosive growth!
Hope you enjoyed!
